Medical imaging systems often make use of a large number of separate radiation detectors in order to provide high resolution imaging. For example, a typical positron emission tomography (PET) system may include hundreds or thousands of separate detectors. Furthermore, radiation imaging is often performed in conjunction with other imaging modalities (e.g., magnetic resonance imaging (MRI)) that can complicate the task of dealing with the large number of radiation detector channels. For example, MRI systems can generate significant levels of electrical interference. Accordingly, methods of multiplexing the detector channels, or otherwise reducing the cost/complexity of radiation imaging systems are of great interest.
One way to reduce the number of detector channels is considered in US 2004/0200966. In this work, a scintillation crystal array having M elements is coupled to a detector array having N<M elements. Each scintillation crystal is coupled to a distinct set of the detectors. As a result, the combination of detectors that provides signals in response to detected radiation serves to identify the relevant scintillation crystal. Although this approach reduces the number of electrical channels to less than the number of scintillation crystals, it can be difficult to achieve a large reduction of the number of channels in practice.
More specifically, it can be difficult to provide the required coupling of many scintillation crystals to each detector in practice. For example, 10 detectors in this approach could theoretically distinguish signals from about 1000 scintillation crystals. However, it would be necessary for each of the detectors to be connected to about 500 scintillation crystals, which presents substantial practical difficulties.
Accordingly, it would be an advance in the art to provide improved multiplexing for radiation imaging systems.